VBS 2 Tox Flashcards
Milkweed
Asclepias spp.
Lily of the Valley
Convallaria majalis
Digitalis purpurea
Foxglove
Nerium oleander
Oleander
Oleander
Oleander
Rhododendron (azalea)
Rhododendron (pieris)
Rhododendron (mountain laurel)
Taxus spp.
Yew
Zygadenus veneosus
Death Camas
Bufo toad
Cane toad lol
Factors that contribute to heart’s susceptibility to injury by toxins?
- level of energy and nutrients needed for normal function
- level of exposure to toxicants
- relatively limited protective metabolic systems
- limited ability to handle structural loss
Mechanisms of Toxicoses in the Heart
- Alteration in conduction
- Alteration in contractile ability
- Alteration in metabolism
- Alteration in ultrastructure
- indirect mechanisms
Cardiac glycoside MOA
- INHIBIT Na/K ATPase
- increases force of contraction
——> - decreased intracellular K+ and increased serum K+
- decreases resting membrane potential
- results in cardiac arrythmias
Cardiac Glycosides
- Foxglove
- Lily of the Valley
- Oleander
- Burning Brush
- Star of Bethlehem
- Milkweed
- Dogbane
- Pheasant’s Eye
Grayanotoxin MOA
Grayanotoxins
Rhododendrons
- azalea
- mountain laurel
- dog laurel
- mountain pieris
- maleberry
- mock azalea
- Labrador tea
Ionophore MOA
*in simple-stomach species
- creating artificial Na channels in the sarcolemma
- increasing Na influx
- increases force of contraction
Nitrate Toxicity MOA
Cyanide Toxicity MOA
Alkaloid Toxicity MOA
Therapeutic Index
- range of doses at which a medication is effective without unacceptable adverse events
- ratio of median lethal dose to median effective dose
- therapeutic index of 1= lethal dose and effective dose are the same (very bad)
***high therapeutic index means the drug is very safe
Volume of Distribution
- represents an individual drug’s propensity to remain in the plasma or redistribute to other tissue compartment
Vd= amt of drug in the body/plasma conc. of drug
***higher the Vd the greater the degree of drug distribution into the tissues
